## 环境
ElasticSearch 。
如果使用 docker-compose 部署 ElasticSearch 集群，可以参考我的这篇文章 [docker-compose部署ElasticSearch集群](https://zysite.top/archives/elasticsearch-docker-compose-install)
## 依赖
pom.xml 依赖文件如下：springboot 版本是 2.4.0.RELEASE 。
```xml
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
<!-- elasticsearch starter -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
<version>2.4.3</version>
</dependency>
<!--lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.47</version>
</dependency>
</dependencies>
```
## 配置
我这里采用 Java 配置和配置文件相结合的方式进行配置，创建配置类如下：
```java
/**
* es配置类
*
* @author Leo
* @create 2021/3/2 10:51
**/
@Configuration
public class ElasticsearchConfig {
@Value("${elasticsearch.schema}")
private String schema;
@Value("${elasticsearch.address}")
private String address;
@Value("${elasticsearch.connectTimeout}")
private int connectTimeout;
@Value("${elasticsearch.socketTimeout}")
private int socketTimeout;
@Value("${elasticsearch.connectionRequestTimeout}")
private int tryConnTimeout;
@Value("${elasticsearch.maxConnectNum}")
private int maxConnNum;
@Value("${elasticsearch.maxConnectPerRoute}")
private int maxConnectPerRoute;
@Value("${elasticsearch.userName}")
private String userName;
@Value("${elasticsearch.password}")
private String password;
/**
* Es Rest客户端配置
* @return
*/
@Bean
public RestHighLevelClient restHighLevelClient() {
//认证信息
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(userName, password));
//解析地址
List<HttpHost> hostLists = new ArrayList<>();
String[] hostList = address.split(",");
for (String addr : hostList) {
String host = addr.split(":")[0];
String port = addr.split(":")[1];
hostLists.add(new HttpHost(host, Integer.parseInt(port), schema));
}
HttpHost[] httpHost = hostLists.toArray(new HttpHost[]{});
RestClientBuilder builder = RestClient.builder(httpHost);
//连接超时配置
builder.setRequestConfigCallback(requestConfigBuilder -> {
requestConfigBuilder.setConnectTimeout(connectTimeout);
requestConfigBuilder.setSocketTimeout(socketTimeout);
requestConfigBuilder.setConnectionRequestTimeout(tryConnTimeout);
return requestConfigBuilder;
});
//连接数、认证信息配置
builder.setHttpClientConfigCallback(httpClientBuilder -> {
httpClientBuilder.setMaxConnTotal(maxConnNum);
httpClientBuilder.setMaxConnPerRoute(maxConnectPerRoute);
httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
return httpClientBuilder;
});
return new RestHighLevelClient(builder);
}
}
```
配置文件`application.yml`内容如下：
```yaml
spring:
application:
name: hello-elasticsearch
elasticsearch:
schema: http
address: localhost:9200
connectTimeout: 5000
socketTimeout: 5000
connectionRequestTimeout: 1000
maxConnectNum: 50
maxConnectPerRoute: 10
userName:
password:
```
## 测试
### 创建一个实体类
该类对应我们存储进 ES 的数据结构。这里用 Book 做示例
```java
/**
* @author Leo
* @create 2021/6/9 14:58
**/
@Data
@Accessors(chain = true)
@Document(indexName = "books")
public class Book {
@Id
private String id;
@Field(type = FieldType.Text)
private String name;
@Field(type = FieldType.Text)
private String summary;
@Field(type = FieldType.Integer)
private Integer price;
@Field(type = FieldType.Date, format = DateFormat.date)
private LocalDate publishDate;
}
```
我们可以通过注解绑定对象和 ES 中的 index ，以及定义字段的类型等。
### 创建DAO类
该类和我们经常定义的访问数据库的类一样，用于定义访问 ES 的接口。
```java
/**
* @author Leo
* @create 2021/6/9 15:02
**/
@Repository
public interface BookRepository extends ElasticsearchRepository<Book, String> {
/**
* 计算特定name数量
* @param name
* @return
*/
long countByName(String name);
/**
* 通过name查询 也可以用 List 接收
* @param name
* @return
*/
Iterable<Book> findByName(String name);
/**
* 通过name查询，带分页
* @param name
* @param pageable
* @return
*/
Page<Book> findByName(String name, Pageable pageable);
/**
* 模糊查询（忽略大小写）
* @param name
* @return
*/
List<Book> findByNameLike(String name);
/**
* 查询价格低于特定值的记录
* @param price
* @return
*/
Stream<Book> findByPriceLessThan(Integer price);
/**
* 异步查询
* 返回类型可以是：Future/CompletableFuture/ListenableFuture
* @param name
* @return
*/
@Async
CompletableFuture<Book> findOneByName(String name);
}
```
我们不需要实现该接口，就可以操作 ElasticSearch，因为如果我们按照一定的规则定义方法名，参数，返回值类型等，Spring Data 整合 ElasticSearch 模块会自动解析方法含义（可以看到我们的 BookRepository 继承了 ElasticsearchRepository），底层通过 RestHighLevelClient 访问 ES 。完整规则：[Spring官方文档](https://docs.spring.io/spring-data/elasticsearch/docs/4.2.1/reference/html/#elasticsearch.query-methods)
### 创建测试类，测试对应方法
```java
@Slf4j
@RunWith(SpringRunner.class)
@SpringBootTest
public class HelloElasticsearchApplicationTests {
@Resource
private BookRepository bookRepository;
/**
* 新增
*/
@Test
public void testSave() {
bookRepository.save(new Book()
// .setId("1")
.setName("jvm GC原理")
.setPrice(78)
.setPublishDate(LocalDate.of(2015, 7, 23))
.setSummary("详细讲解Java 虚拟机垃圾回收机制及其原理"));
}
/**
* 批量新增
*/
@Test
public void testSaveAll() {
List<Book> books = new ArrayList<>();
for(int i = 0; i < 20; i++) {
books.add(new Book()
.setId(String.valueOf(i))
.setName("Book" + i)
.setPrice(new Random().nextInt(200))
.setPublishDate(LocalDate.now())
.setSummary(String.valueOf(i)));
}
bookRepository.saveAll(books);
}
/**
* 查询单条，查询所有，查询记录数量
*/
@Test
public void testFind() {
// bookRepository.findById("1").ifPresent(book -> log.info(book.toString()));
log.info("count of books : " + bookRepository.count());
// bookRepository.findById("2").ifPresent(book -> log.info(book.toString()));
bookRepository.findAll().forEach(book -> log.info(book.toString()));
}
/**
* 测试分页和排序
*/
@Test
public void testPage() {
bookRepository.findAll(PageRequest.of(0, 10, Sort.by("price").descending()))
.forEach(book -> log.info(book.toString()));
}
/**
* 删除
*/
@Test
public void testDelete() {
bookRepository.deleteById("0");
// bookRepository.deleteAll();
}
/**
* 指定条件计数
*/
@Test
public void testCount() {
String name = "深入理解JVM";
log.info("count of book 《" + name + "》 : " + bookRepository.countByName(name));
}
@Test
public void testFindByName() {
String name = "深入理解JVM";
bookRepository.findByName(name).forEach(book -> log.info(book.toString()));
}
@Test
public void testFindByNamePageable() {
String name = "深入理解JVM";
bookRepository.findByName(name, PageRequest.of(0, 1)).forEach(book -> log.info(book.toString()));
}
/**
* 模糊查询
*/
@Test
public void testFindByNameLike() {
String name = "JVM";
bookRepository.findByNameLike(name).forEach(book -> log.info(book.toString()));
}
/**
* 比较查询
*/
@Test
public void testFindByPriceLessThan() {
int price = 100;
bookRepository.findByPriceLessThan(price).forEach(book -> log.info(book.toString()));
}
/**
* 异步执行
*/
@Test
public void testAsync() {
String name = "深入理解JVM";
CompletableFuture<Book> future = bookRepository.findOneByName(name);
future.whenComplete((book, throwable) -> {
if (throwable != null) {
log.error("error! reason : ", throwable);
} else {
log.info("Async query get Result: " + book.toString());
}
});
}
}
```
如果安装了 Kibana 的话，我们可以进入 Kibana 后台 [http://localhost:5601/app/home#/](http://localhost:5601/app/home#/)，通过 Kibana Dev Tools 中的 Console 界面来方便查询数据。
或者通过 Kibana Discover 界面以列表的形式查看所有数据。
SpringBoot整合ElasticSearch
